Protective helmet



FIG. 1 is a perspective view of a football helmet of the present invention;

FIG. 2 is a right side view thereof, the left side being a mirror image;

FIG. 3 is a front view thereof;

FIG. 4 is a back view thereof;

FIG. 5 is a top plan view thereof; and,

FIG. 6 is a bottom plan view thereof.

The broken lines in the drawings are for illustrative purposes only and form no part of the claimed design. 

We claim the ornamental design for a protective helmet, as shown and described. 